The problem of HIV infection in adolescence continues to grow despite public health efforts to reduce risk behaviors related to the acquisition and transmission of the virus. Developmental characteristics make HIV infection and transmission a concern for all adolescents, but there are subgroups of youths, especially in more urban settings, who are at relatively greater risk because of elevated levels of HFV-relevant risk behaviors. Large scale information-based programs often have led to greater awareness of HIV risks, but have had relatively limited success in preventing or reducing future engagement in HIV-risk taking behaviors. Individualized, contingency based interventions focused on skills training have shown promise, yet feasibility is limited by the high costs of such endeavors. These costs theoretically could be reduced with the identification of individuals most vulnerable to engaging in HIV-risk taking behaviors. To aid in such identification, we have developed an easy-to-use, adolescent appropriate, behavioral assessment tool to index risky behavior termed the Balloon Analogue Risk Task (BART). Previous research with young adults and middle adolescents has shown that riskiness on the task is related to current engagement in HIV risk-taking behaviors (e.g., unprotected sexual intercourse) as well as other risk-taking behaviors (e.g., smoking, delinquent behavior). In the next step in this research, we aim to determine if riskiness on the BART in younger adolescents can be used to predict future engagement in HIV risk-taking behaviors. Specifically, we propose to follow 240 11-12 year olds over a 5-year period including an initial assessment with 3 follow-up assessments occurring at 1 year intervals). We expect that the behavioral index of "riskiness" on the baseline administration of the BART will predict: the emergence of HIV risk behaviors at follow-up assessments above and beyond that provided with a battery of more traditional selfreport measures assessing demographics (e.g., SES, gender, race), self-report measures of relevant individual difference variables (e.g., impulsivity, sensation seeking), cognitive processes (e.g., risk perception, HIV knowledge), environmental factors (e.g., life events, parental monitoring, peer influence), as well as developmental precursors to risk taking behavior (e.g., attention-deficit/hyperactivity, oppositional/defiant, and conduct disorder symptom severity. As a secondary question, we are interested in the extent to which riskiness on the BART and the measures within the self-report battery are stable across follow-up administrations, including the relationship of these changes to changes in real-world risk-taking behaviors.